Enclosed electric switch



June 20, 1961 T. F. BROWN 2,989,612

ENCLOSED ELECTRIC SWITCH Original Filed Dec. 11, 1957 4 Sheets-Sheet 1 June 20, 1961 T. F. BROWN 2,989,612

ENCLOSED ELECTRIC SWITCH Original Filed Dec. 11, 1957 4 Sheets-Sheet 2 June 20, 1961 T. F. BROWN 2,

ENCLOSED ELECTRIC SWITCH Original Filed Dec. 11, 1957 4-Sheets-Sheet 5 June 20, 1961 BR 2,989,612

I ENCLOSED ELECTRIC SWITCH Original Filed Dec. 11, 1957 4 Sheets-Sheet 4 Fig.6. Figs 83 I I I I I ---'B5 l I l l l l l Fig.7. I -es' Fig.9. Fig.lO.

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United States Patent 3 "Claims. (Cl. 200-168) This'invention relates, generally, to enclosed electric switches and, more particularly, to enclosed switches suitable for utilization in panelboard and switchboard structures.

This application is a division of my copending application Serial No. 702,029, filed December 11, 1957.

In order to protect the apparatus and the operating personnel, manually operable circuit breakers and switches are enclosed in metal boxes or cabinets which may be mounted in a panelboard or switchboard structure. The circuit breaker or switch mechanism is operated by an operating member or handle composed of a molded insulating material which is actuated by an external handle on the door of the enclosing cabinet. The operating mechanism in the door is disengaged from the breaker or switch handle when the door is opened.

It is desirable to preclude the possibility of breaking the operating member of the switch when the door of the cabinet is closed. It is also desirable that the external handle should always indicate the position of the switch handle when the door is closed, thereby signifying whether the switch is opened or closed.

In order to accomplish the first purpose, mechanisms of the type described in Patent No. 2,550,125, issued April 24, 1951 to A. E. Schueler et al. were developed. In the aforesaid mechanism two spaced spring arms were provided for engaging the breaker operating member or handle. The resilience of the spring arms permitted the cover to be closed regardless of the respective positions of the external handle and the breaker handle without damaging the breaker handle because the spring arms yielded upon engaging the breaker handle it the two handles were not in corresponding operative positions. A spring arm remained in a deflected position until the external handle was actuated to the position corresponding to the position of the breaker handle at which time the breaker handle entered the space between the spring arms. However, in the meantime, the external handle did not indicate the position of the breaker handle and there was a possibility of someone being misled into thinking that the breaker was open when it was actually closed or vice versa.

For applications where it was very important that the external handle should always indicate the correct position of the breaker handle when the cover was closed, mechanisms, such as those described in a copending application of I. G. Portrnan et al., Serial No. 481,622, filed January 13, 1955, now Patent No. 2,806,098, were developed. In one such mechanism, a plate was slidably mounted on the inside of the cover and an operating plate was adjustably attached to the inner side of the slidable plate which was reciprocated by means of the external handle. Two spaced rigid operating arms were attached to the operating plate. The breaker handle was disposed in the space between the opposing ends of the operating arms when the cover was closed. Since the operating arms were rigid, there was danger of breaking the molded breaker handle by it being struck by one of the operating arms if the positions of the external handle and the breaker handle did not correspond when an attempt was 'iade to lose the cover.

An object of the invention is to provide an enclosed "ice electric switch having an external operating handle mounted on the door of the enclosure, which handle must be in a position corresponding to the position of the switch mechanism handle to permit closing the door of the enclosure.

A further object of the invention is to prevent breakage of the molded switch handle when attempting to close the cabinet door with the external handle and the switch handle in dissimilar positions.

Another object of the invention is to utilize parts of the actuating mechanism for the switch as intermediate bearing supports for an insulating cross-bar of the switch.

A still further object of the invention is to provide a simplified and improved toggle mechanism for actuating the contact members of the switch.

Still another object of the invention is to provide an operating mechanism which may be utilized with enclosed switches of different ratings.

Other objects of the invention will be explained fully hereinafter or will be apparent to those skilled in the art.

In accordance with one embodiment of the invention, two spaced blocks, composed of an elastomeric or rubber-likematerial, are mounted in a slidable member to engage the molded handle of an enclosed switch, thereby operating the switch by "means of an external handle on the cover of the enclosure. The operating mechanism is so constructed that slides and blocks of different sizes may be utilized with switches of different ratings. blocks are wide enough to prevent closing the door of the enclosure unless the external operating handle and the switch handle are in corresponding positions, but the switch handle is not broken if it is struck by one of the blocks. Spaced supports for the toggle mechanism of the switch function as bearing members for the cross bar to which switch arms are attached.

For a better understanding of the nature and objects of the invention, reference may be had to the following detailed description taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a reduced view of a panelboard structure containing switch units embodying the principal features of the invention;

FIG. 2 is a view, partly in section and partly in eleva-' tion, of one of the switch units, the contact members of the switch being in the off or openposition;

FIG. 3 is a view, in plan, of the operating mechanism for the switch, the mechanism being in on or closed position;

FIG. 4 is a view, partly in section and partly in plan, of the main base assembly for the switch, the actuating handle being removed for clearance;

FIG. 5 is a view, in section, taken along the lines VV in FIG. 4;

FIGS. 6 and 7 are enlarged detail views of an operating clip utilized in the operating mechanism;

FIGS. 8, 9 and 10 are enlarged detail views of a rubber bushing or block utilized in the operating clip;

FIG. 11 is an enlarged detail view of a cradle retaining spring utilized in the toggle mechanism for the switch; and

FIG. 12 is an enlarged detail view of a mounting plate for the toggle mechanism.

Referring to the drawings, and particularly FIG. 1, the

The.

3 cation, Serial No. 700,635, filed December 4, 1957. As shown, two complete switch assemblies of the smaller ratings may be housed in one box or cabinet.

As shown in FIG. 2, each box or cabinet 11 has two openable covers 15. Each cover provides access to one of the. switch assemblies contained within the cabinet 11. An external operating handle 16 is rotatably mountedon each cover 15. A spring-biased latch 17 is provided for retaining each cover 15 closed. As will be described more fully hereinafter, an interlocking device is also provided for normally retaining the cover 15 closed when the switch is in the on position.

Each switch assembly comprises a main base 18 and a secondary or fuse base 19 which is spaced from the main base 18 in the cabinet 11. Line terminal members 21, contact members 22, are extinguishers 23 and an actuating mechanism 24 for a three-pole switch are mounted on the main base 18. A fuse clip 25 for each pole is also mounted on the base 18. Another fuse clip 26 and a load terminal connector 27 for each pole are mounted on the secondary base 19. The bases 18 and 19 are preferably molded from a suitable insulating material.

As shown more clearly in FIG. 5, each pole of the switch structure comprises a line terminal assembly which includes the terminal 21, a fixed contact member 21 which may be brazed to the terminal 21, and an arc runner 20 attached to the terminal 21 by a screw 28 which also re tains the terminal 21 on the base 18. The screw 28 is threaded into a metal insert 29 provided in the base 18.

The movable contact member 22 for each pole is secured to a contact arm 31 which is pivotally mounted on an actuating arm 32 attached to an insulating cross-bar or shaft 33. The contact arm 31 is pivoted on a pin 34 disposed in the actuating arm 32. The contact arm 31 has a clearance hole therethrough for a pivot pin 35 to which a toggle mechanism is connected as will be described more fully hereinafter. The clearance hole about the pin 35 limits the movement of the contact arm 31 about its pivot point 34. A torsion spring 36, which surrounds the pin 35 and has one end engaging the shaft 33, is provided for maintainng a predetermined contact pressure between the movable contact member 22 and the fixed contact member 21' when the contact members are closed.

A flexible conductor 37 connects the contact arm 31 to an angle-shaped conductor 38 to which the fuse clip 25 is attached. The conductor 38 is attached to the base 18 by screws 39 threaded into metal inserts 29 in the base 18. Thus, an electrical crcuit is established between the terminal member 21 and the fuse clip 25 when the contact members 22 and 21' are engaged. A fuse (not shown) may be inserted in the fuse clips 25 and 26, thereby completing the circuit through each pole of the switch.

The toggle mechanism for actuating the movable contact members of the switch is supported between a pair of spaced mounting plates 41, one of which is shown in detail in FIG. 12. Each mounting plate has an angularlyextending foot 42 for attaching the plate to the base 18 by screws 43 as shown most clearly in FIG. 4. The upper ends of the two plates 41 are secured together by a spacing stud 44.

A cradle member 45 is disposed between the plates 41 in a fixed position. The cradle member is mounted on a pin 46 which extends between the mounting plates 41. One end of the cradle member 45 is attached to the spacing stud 44. The other end of the cradle member is anchored to the mounting plates 41 by means of a generally V-shaped spring 47 which-is shown in detail in FIG. 11. The ends of the legs of the V-shaped spring 47 have angularly extending projections 48 thereon which are disposed in holes 49 provided in the mounting plates 41. The spring tension of the V-shaped member biases the legs of the V outwardly, thereby retaining the projections 48 in the holes 49. Thus, the spring 47 may be readily assembled in the toggle mechanism.

Toggle links 51 are pivotally connected to the cradle 4 1 member 45 by a pin 52. Toggle links 53 are pivotally connected to the actuating arm 32 of the middle pole of the switch by means of the pin 35. The toggle links 51 and 53 are pivotally connected together by a toggle pin 54. The actuating arm 32 is secured to the shaft or crossbar 33 by a staple 55.

The cross-bar 33 is composed of an insulating material in order to electrically insulate the poles of the switch from each other. Each end of the shaft or cross-bar 33 is mounted in a bearing bracket 56 attached to the base 18 by screws 57. In order to prevent bending the cross bar 33, additional support for the bar is provided by the mounting plates 41. As shown most clearly in FIGS. 4 and 12 each mounting plate has a bearing surface 58 for a grooved portion 59 of the shaft 33. Thus, deflection of the shaft 33 during operation of the switch is prevented.

The ends of the legs of a generally U-shaped operating lever 61 are pivotally mounted in rounded portions 62 of the mounting plates 41. Overcenter toggle springs 63 are connected between the toggle pin 54 and the base of the U-shaped operating lever 61. An actuating handle 64 is attached to the base of the lever 61 for operating the toggle mechanism, thereby actuating the movable contact members of the switch.

In order to provide for operating the switch by means of the external handle 16, a cam shaped plate 71 is attached to the inner end of a shaft of the handle which extends through the cover 15. The plate is attached to the shaft by means of a screw 70. The plate 71 carries a pin or anti-friction roller 72 which is disposed in a slot 73 in a slidable operating plate 74. The plate 74 is supported for sliding movement between grooved studs 75 and 76. The studs 75 are attached to a supporting plate 77 which, in turn, is attached to the inside of the cover 15 by screws 78. The studs 76 are attached to a second supporting plate 79 which is attached to the first supporting plate 77 and the cover 15 by screws 81.

As shown in FIG. 3, additional holes 82 are provided in the first supporting plate 77 for attaching the plate 79 to the plate 77 in a different position from that shown in FIG. 3. Thus, the position of the studs 76 may be changed to permit a wider operating plate 74 to be utilized for switches of a higher current rating which require a heavier and stronger operating mechanism.

As explained hereinbefore, it is desirable to prevent the cover of the cabinet from being completely closed unless the external handle 16 and the actuating handle 64 are in corresponding positions. As also explained it is desirable to prevent breaking the actuating handle 64, which is composed of a rigid molded resinous plastic insulating material, when an attempt is made to close the cover 15 without the external handle 16 and the handle 64 being in corresponding positions.

In order to provide both of the foregoing features in the same operating mechanism, an operating clip 83 is attached to the operating plate 74 by means of screws or rivets 84. Two bushings or blocks 85 are mounted in the operating clip 83 which is shown in detail in FIGS. 6 and 7. The blocks 85 are made from a rubbery or otherwise elastomeric organic material which has the property of being soft or elastic enough to prevent breakage of the rigid molded resinous material of the handle 64 when the cover 15 is slammed closed and the lower surface 85' of either block 85 comes down on the top of the handle 64. At the same time, the portions 85 of elastorneric material are rigid enough that the top of the handle 64 cannot be pressed up into either portion far enough to permit the cover to be closed and the cover latch 17 engaged, without the top of the handle 64 being properly positioned in the slot or space between the two portions 85. Furthermore, the elastomeric-material has the property of being resilient or elastic in that its surface 85' returns to its original position and shape after it has been deformed by being banged down on the top of the handle 64. Various elastomeric organic materials having such properties may be used, such for example as natural or synthetic rubbers having a Shore durometer A hardness as low as 50 or 60 or as high as 75 or 80. A preferred material for the blocks 85 is composed of rubber or a rubber compound such as GRS or Buna S synthetic rubber having a Shore durometer A hardness of approximatel 70.

y The rubberlike material is particularly suitable for this purpose in view of its elastic resilience or ability to absorb energy elastically. Therefore, it absorbs the shock resulting from one of the blocks 85 striking the handle 64 in case an attempt is made to close the cover 15 without the handle 16 and the handle 64 being in corresponding positions. The blocks 85 are sufficiently rigid to prevent closing the cover, but not rigid enough to break the handle 64.

As shown in FIG. 6 the operating clip 83 is provided with openings 86 in which the blocks 85 are inserted. As shown in FIGS. 8, 9 and 10, the blocks 85 are so shaped and proportioned that they may be inserted into the clip 83 prior to its attachment to the operating plate 74. The blocks 85 are retained in the clip 83 when it is attached to the plate 7 4.

As shown in FIG. 2 the handle 64 is disposed in the space between the blocks 85 when the cover 15 is fully closed. Thus, rotation of the handle 16 rotates the carnshaped plate 71 which reciprocates the plate 74 and the operating clip 83 by means of the pin and slot connection 72-73. The blocks 85 engage the actuating handle 64 to operate the switch.

In order to normally prevent opening the cover 15 while the contact members of the switch are closed, an interlocking latch 87 is pivotally attached to the cover 15 by means of a screw 88, the head of which is disposed on the outside of the cover and the inner end of which is fixed to the latch so that the latch will turn with the screw. The interlocking latch 87 is biased by a spring 89 to engage a locking element 91 attached to the side of the cabinet 11, thereby retaining the cover closed. When the handle 16 is actuated to the open cover position, a projection 92 on the cam plate 71 engages the interlocking latch 87 to disengage the latch from the locking element 91, thereby permitting the cover to be opened when the contact members of the switch are open. However, the interlocking latch 87 may be actuated by means of the screw 88 to which the latch 87 is attached to release the latch when the operating handle 16 is in the on position, thereby permitting access to the switch by a person who knows the function of the screw 88.

From the foregoing description it is apparent that the present invention provides a switch structure having the desirable safety feature of ensuring that the external operating handle and the switch handle are in corresponding positions when the cover of the enclosure for the switch is fully closed. Furthermore, the present invention precludes the possibility of breaking the switch actuating handle by attempting to close the cover when the external handle and the switch handle are not in corresponding positions. The present invention provides an operating mechanism which is simple in construction and it may be readily adapted for operating switches of different ratings and sizes.

Since numerous changes may be made in the abovedescribed construction, and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. In a multipole circuit interrupter, in combination, an insulating base, a plurality of fixed contact members mounted on the base in spaced relation, a corresponding number of contact arms having contact members thereon for engaging said fixed contact members, a rotatable shaft for actuating said contact arms, a pair of spaced mounting plates attached to said base and having hearing surfaces thereon for said shaft, an actuating arm secured to the shaft, a cradle member disposed between said mounting plates in a fixed position, toggle links con necting the cradle member to the actuating arm, a generally V-shaped spring member connecting one end of the cradle member to the mounting plates, an operating lever pivoted on said mounting plates, overcenter toggle springs connected between said lever and said toggle links, and an actuating handle on said lever.

2. In a multipole circuit interrupter, in combination, an insulating base, a plurality of fixed contact members mounted on the base in spaced relation, a corresponding number of contact arms having contact members thereon for engaging said fixed contact members, a rotatable shaft for actuating said contact arms, bearing brackets mounted on the base for supporting the ends of said shaft, a pair of spaced mounting plates attached to the base and having bearing surfaces thereon for supporting the shaft between said bearing brackets, an actuating arm secured to the shaft, a cradle member disposed between said mounting plates in a fixed position, toggle links connecting the cradle member to the actuating arm, a spring member having two legs and an intermediate portion connecting one end of the cradle member to said spaced mounting plates, an operating lever pivoted on said mounting plates, overcenter toggle springs connected between said lever and said toggle links, and an actuating handle on said lever.

3. In a multipole circuit interrupter, in combination, an insulating base, a plurality of fixed contact members mounted on the base in spaced relation, a corresponding number of contact arms having contact members thereon for engaging said fixed contact members, a rotatable shaft for actuating said contact arms, bearing brackets mounted on the base for supporting the ends of said shaft, a pair of spaced mounting plates attached to the base and having bearing surfaces thereon for supporting the shaft between said bearing brackets, an actuating arm secured to the shaft, a cradle member disposed between said mounting plates in a fixed position, toggle links connecting the cradle member to the actuating arm, a generally V-shaped spring member having its intermediate portion attached to one end of the cradle and angularly extending portions on the ends of its legs engaging said mounting plates, a generally U-shaped operating lever having its legs pivoted on said mounting plates, overcenter toggle springs connected between the base of the U-shaped operating lever and the toggle links, and an actuating handle attached to the base of the operating lever.

References Cited in the file of this patent UNITED STATES PATENTS 1,955,327 Dorfman Apr. 17, 1934 2,204,409 Gano lune ll, 1940 2,690,486 Wilckens Sept. 28, 1954 2,769,049 Edmunds Oct. 30, 1956 2,810,048 Christensen Oct. 15. 1957 

